Infection-triggered familial or recurrent cases of acute necrotizing encephalopathy caused by mutations in a component of the nuclear pore, RANBP2

Nuclear pore dysfunction and disease: a complex opportunity

The separation of genetic material from bulk cytoplasm has enabled the evolution of increasingly complex organisms, allowing for the development of sophisticated forms of life. However, this complexity has created new categories of dysfunction, including those related to the movement of material between cellular compartments. In eukaryotic cells, nucleocytoplasmic trafficking is a fundamental biological process, and cumulative disruptions to nuclear integrity and nucleocytoplasmic transport are detrimental to cell survival. This is particularly true in post-mitotic neurons, where nuclear pore injury and errors to nucleocytoplasmic trafficking are strongly associated with neurodegenerative disease. In this review, we summarize the current understanding of nuclear pore biology in physiological and pathological contexts and discuss potential therapeutic approaches for addressing nuclear pore injury and dysfunctional nucleocytoplasmic transport.

Clinical characteristics and genetic analysis of children with Omicron BF.7.14 type novel coronavirus-related acute necrotizing encephalopathy

Background

To explore the clinical characteristics, etiological factors, and clinical-related genetic variant of children with acute necrotizing encephalopathy (ANE) related to the Omicron BF.7.14 novel coronavirus.

Methods

Genomic variations were detected through whole exome sequencing. Additionally, we summarized the clinical data to explore the inheritance patterns associated with novel coronavirus-related ANE.

Results

This study included four patients (2 males and 2 females) with an average age of 2.78 ± 1.93 years. All the patients had prodromal symptoms of Omicron BF.7.14 virus infection, and exhibited symptoms such as altered consciousness, seizures and cognitive/language disturbances. Cranial MRI scans revealed damage to the thalamus, basal ganglia and brainstem. The cerebrospinal fluid (CSF) cell counts were nearly normal, but protein level in CSF increased significantly. Genetic analysis revealed a novel truncated variant of CRMP2 gene in one patient who suffered more severe coma score and prognosis and dead in the later stages. All children exhibited a decrease in the absolute count of T lymphocytes, helper T cells, suppressor T cells, and NK cells to varying degrees. Furthermore, levels of cytokines, including IL-1 β, IL-5, IL-6 and IL-8 were significantly elevated in the CSF, especially in patient with truncated variant of CRMP2 gene.

Conclusion

The Omicron BF.7.14 type novel coronavirus can lead to ANE, characterized by T cell immunosuppression and a significant increase in cytokine levels in the CSF. The truncated variation of CRMP2 gene may affect the prognosis of ANE by affecting the migration of cerebral T cells.

Novel islands of GGC and GCC repeats coincide with human evolution

BACKGROUND

Because of high mutation rate, overrepresentation in genic regions, and link with various neurological, neurodegenerative, and movement disorders, GGC and GCC short tandem repeats (STRs) are prone to natural selection. Among a number of lacking data, the 3-repeats of these STRs remain widely unexplored.

RESULTS

In a genome-wide search in human, here we mapped GGC and GCC STRs of ≥3-repeats, and found novel islands of up to 45 of those STRs, populating spans of 1 to 2 kb of genomic DNA. RGPD4 and NOC4L harbored the densest (GGC)3 (probability 3.09061E-71) and (GCC)3 (probability 1.72376E-61) islands, respectively, and were human-specific. We also found prime instances of directional incremented density of STRs at specific loci in human versus other species, including the FOXK2 and SKI GGC islands. The genes containing those islands significantly diverged in expression in human versus other species, and the proteins encoded by those genes interact closely in a physical interaction network, consequence of which may be human-specific characteristics such as higher order brain functions.

CONCLUSION

We report novel islands of GGC and GCC STRs of evolutionary relevance to human. The density, and in some instances, periodicity of these islands support them as a novel genomic entity, which need to be further explored in evolutionary, mechanistic, and functional platforms.

A case report and literature review on tocilizumab-cured acute necrotizing encephalopathy caused by influenza A virus

Introduction

Acute Necrotizing Encephalopathy (ANE), is a kind of severe Central Nervous System Disease. The commonest pathogen is the influenza virus. The pathogenesis of ANE is bound up to genetic susceptibility and cytokine storm. Interleukin-6 (IL-6) is deemed as the core function in cytokine storm of ANE and that plays a significant role in evaluating the severity of Influenza-Related ANE. Tocilizumab, an IL-6 antagonist, is known to be safe and effective in the treatment of ANE when used early and has an essential role in improving prognosis and preventing disability.

Case report

This case reports a 2 year 10 month old boy who developed ANE after being infected with influenza A virus (H1N1-2019). After treatment with Tocilizumab, the child's consciousness was clear, no convulsions occurred, the movement of limbs was improved, and the lesions of encephalopathy were significantly reduced.

Conclusion

The early use of Tocilizumab is safe and effective for the treatment of ANE caused by influenza virus.

Pediatric neuroinflammatory diseases in the intensive care unit

Inflammatory disorders of the central nervous system (CNS) include a wide spectrum of autoimmune, autoinflammatory, and paraneoplastic diseases. While many affected patients require acute hospital admission, a subset may present with severe neurological symptoms requiring intensive care unit (ICU) escalation due to disordered consciousness, respiratory failure, status epilepticus, intracranial hypertension, and/or severe autonomic dysregulation.

A Rare Case of COVID-19 Related Acute Necrotizing Encephalopathy With the RANBP2 Mutation in a Pediatric Patient

Acute necrotizing encephalopathy (ANE) is a rare childhood neurological disorder. The familiar type of ANE (ANE1) is associated with a mutation in the RANBP2 gene. Both SARS-CoV-2 and RANBP2 mutations are responsible for the manifestation of a hyper-inflammatory response that invades the central nervous system and plays a key role in the rapid progression of encephalopathy.

Nucleoporin Seh1 controls murine neocortical development via transcriptional repression of p21 in neural stem cells

Mutations or dysregulation of nucleoporins (Nups) are strongly associated with neural developmental diseases, yet the underlying mechanisms remain poorly understood. Here, we show that depletion of Nup Seh1 in radial glial progenitors results in defective neural progenitor proliferation and differentiation that ultimately manifests in impaired neurogenesis and microcephaly. This loss of stem cell proliferation is not associated with defects in the nucleocytoplasmic transport. Rather, transcriptome analysis showed that ablation of Seh1 in neural stem cells derepresses the expression of p21, and knockdown of p21 partially restored self-renewal capacity. Mechanistically, Seh1 cooperates with the NuRD transcription repressor complex at the nuclear periphery to regulate p21 expression. Together, these findings identified that Nups regulate brain development by exerting a chromatin-associated role and affecting neural stem cell proliferation.

A 5-year-old boy with super-refractory status epilepticus and RANBP2 variant warranting life-saving hemispherotomy

Focal cortical dysplasia (FCD) represents the most common cause of drug-resistant epilepsy in adult and pediatric surgical series. However, genetic factors contributing to severe phenotypes of FCD remain unknown. We present a patient with an exceptionally rapid development of drug-resistant epilepsy evolving in super-refractory status epilepticus. We performed multiple clinical (serial EEG, MRI), biochemical (metabolic and immunological screening), genetic (WES from blood- and brain-derived DNA), and histopathological investigations. The patient presented 1 month after an uncomplicated varicella infection. MRI was negative, as well as other biochemical and immunological examinations. Whole-exome sequencing of blood-derived DNA detected a heterozygous paternally inherited variant NM_006267.4(RANBP2):c.5233A>G p.(Ile1745Val) (Chr2[GRCh37]:g.109382228A>G), a gene associated with a susceptibility to infection-induced acute necrotizing encephalopathy. No combination of anti-seizure medication led to a sustained seizure freedom and the patient warranted induction of propofol anesthesia with high-dose intravenous midazolam and continuous respiratory support that however failed to abort seizure activity. Brain biopsy revealed FCD type IIa; this finding led to the indication of an emergency right-sided hemispherotomy that rendered the patient temporarily seizure-free. Postsurgically, he remains on antiseizure medication and experiences rare nondisabling seizures. This report highlights a uniquely severe clinical course of FCD putatively modified by the RANBP2 variant. PLAIN LANGUAGE SUMMARY: We report a case summary of a patient who came to our attention for epilepsy that could not be controlled with medication. His clinical course progressed rapidly to life-threatening status epilepticus with other unusual neurological findings. Therefore, we decided to surgically remove a piece of brain tissue in order to clarify the diagnosis that showed features of a structural brain abnormality associated with severe epilepsy, the focal cortical dysplasia. Later, a genetic variant in a gene associated with another condition, was found, and we hypothesize that this genetic variant could have contributed to this severe clinical course of our patient.

A Case of Acute Necrotizing Encephalopathy With Multiple Organ Failure Following COVID-19

Neurological complications are frequent non-respiratory complications associated with coronavirus disease 2019 (COVID-19), and acute encephalopathy (AE) has been reported to occur in 2.2% of patients. Among many phenotypes of AEs, acute necrotizing encephalopathy (ANE) is associated with multiple organ failure (MOF), leading to severe neurological morbidity and mortality. A previously healthy seven-year-old girl presented with a one-day history of fever followed by 12 hours of vomiting and altered consciousness. On arrival, the patient was in shock. Blood tests revealed severe acute liver failure and kidney injury, accompanied by coagulopathy. The serum interleukin-6 levels were also elevated. PCR testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was positive. A head CT scan showed heterogeneous low-density areas in the bilateral thalamus, without brainstem involvement. She was diagnosed as ANE complicated with MOF (ANE severity score = 6). Intravenous methylprednisolone and therapeutic plasma exchange (TPE) were initiated with neurocritical care. After the introduction of TPE, hemodynamics improved rapidly, followed by gradual improvement in neurological manifestations. Upon follow-up after two months, no neurological or systemic sequelae were noted. Although further studies are needed, our case suggests that early immunomodulatory therapy and TPE may have contributed to the improvement in ANE and MOF associated with COVID-19.

RanBP2/Nup358 Mediates Sumoylation of STAT1 and Antagonizes Interferon-α-Mediated Antiviral Innate Immunity

Type I interferon (IFN-I)-induced signaling plays a critical role in host antiviral innate immune responses. Despite this, the mechanisms that regulate this signaling pathway have yet to be fully elucidated. The nucleoporin Ran Binding Protein 2 (RanBP2) (also known as Nucleoporin 358 KDa, Nup358) has been implicated in a number of cellular processes, including host innate immune signaling pathways, and is known to influence viral infection. In this study, we documented that RanBP2 mediates the sumoylation of signal transducers and activators of transcription 1 (STAT1) and inhibits IFN-α-induced signaling. Specifically, we found that RanBP2-mediated sumoylation inhibits the interaction of STAT1 and Janus kinase 1 (JAK1), as well as the phosphorylation and nuclear accumulation of STAT1 after IFN-α stimulation, thereby antagonizing the IFN-α-mediated antiviral innate immune signaling pathway and promoting viral infection. Our findings not only provide insights into a novel function of RanBP2 in antiviral innate immunity but may also contribute to the development of new antiviral therapeutic strategies.

Clinical characteristics and prognostic analysis of acute necrotizing encephalopathy of childhood: a retrospective study at a single center in China over 3 years

Objective

Acute Necrotizing Encephalopathy of Childhood (ANEC) is a rare, fulminant neurological disease in children with unknown mechanisms and etiology. This study summarized the clinical characteristics, treatment, and prognosis of ANEC through a retrospective analysis, providing insights into the ANEC early diagnosis and prognosis assessment.

Methods

Clinical data of children diagnosed with ANEC at the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University from July 1, 2020, to June 30, 2023, were retrospectively analyzed.

Results

There were 25 cases, 14 males and 11 females, with a median age of 3 years. Hospital admissions were mainly in the winter (14/25, 56%) and spring (9/25, 36%). All patients presented with varying degrees of fever and altered consciousness, with 92% (23/25) experiencing high body temperatures (>39.1°C) and 88% (22/25) having a Glasgow coma scale (GCS) score of ≤8. Seizures were observed in 88% (22/25) of patients. Laboratory findings indicated 100% B lymphocyte activation (14/14), and 78% (14/18) of patients showed cytokine storm (interleukin (IL)-6, IL-8, IL-10, interferon (IFN)-α). Neuroimaging showed symmetrical thalamus involvement, commonly involving basal ganglia and brainstem regions. Viral infection (23/24, 96%) was the predominant etiological finding, with 42% (10/24) of cases due to SARS-CoV-2 infection and 42% (10/24) to influenza A virus infection. Multi-organ dysfunction occurred in 68% (17/25) of patients, and 52% (13/25) died. Correlation analysis revealed the death group exhibited higher proportion of male, lower GCS scores, higher IL-6 level and a greater likelihood of associated brainstem impairment (p < 0.05).

Conclusion

ANEC is more prevalent in the winter and spring, and its etiology may be associated with B lymphocyte activation and cytokine storm following viral infections. Clinical manifestations lack specific features, with fever, consciousness disturbances, and seizures being the main presentations, particularly in cases of high fever and hyperpyrexia. ANEC progresses rapidly and has a high mortality rate. The child's gender, GCS score, IL-6 levels, and the presence of brainstem involvement can serve as important risk factors for assessing the risk of mortality.

Recurrent infection triggered encephalopathy syndrome in a pediatric patient with RANBP2 mutation and severe acute respiratory syndrome coronavirus 2 infection

Introduction

Acute necrotizing encephalopathy (ANE), a fatal subtype of infection-triggered encephalopathy syndrome (ITES), can be triggered by many systemic infections. RANBP2 gene mutations were associated with recurrent ANE.

Case presentation

Here we report a 1-year-old girl with recurrent ITES and RANBP2 mutation. She was diagnosed with influenza-associated encephalopathy and made a full recovery on the first episode. After severe acute respiratory syndrome coronavirus 2 infection, the patient presented with seizures and deteriorating mental status. Brain magnetic resonance imaging revealed necrotic lesions in bilateral thalami and pons. Methylprednisolone, immunoglobulin, and interleukin 6 inhibitors were administered. Her consciousness level was improved at discharge. Nineteen cases of 2019 coronavirus disease-related ANE have been reported, of which 22.2% of patients died and 61.1% had neurologic disabilities. RANBP2 gene mutation was found in five patients, two of whom developed recurrent ITES.

Conclusion

Patients with RANBP2 mutations are at risk for recurrent ITES, may develop ANE, and have a poor prognosis after relapse.

The youngest infant with COVID-19-associated necrotizing encephalitis in Asia: A case report

Acute necrotic encephalopathy in children is a very rare complication of severe acute respiratory syndrome coronavirus 2 infection and has rarely been reported worldwide. A 45-day-old girl was admitted to our hospital with fever and listlessness. A nose swab tested positive for the novel coronavirus nucleic acid, and her cerebrospinal fluid was positive for severe acute respiratory syndrome coronavirus 2. An early head magnetic resonance imaging scan indicated multiple abnormal signals in her bilateral cerebral hemispheres, and encephalitis was diagnosed. Twenty-three days after hospitalization, bilateral cerebral atrophy-like changes were observed on magnetic resonance imaging, with multiple softening lesions in the bilateral cerebral hemispheres, accompanied by convulsions. She was admitted to the hospital for mechanically assisted ventilation, and her condition improved after treatment of her symptoms with antiepileptic medication, anti-infection drugs, glucocorticoids, and immunoglobulins. Acute necrotic encephalopathy associated with severe acute respiratory syndrome coronavirus 2 infection in children should be detected and treated as early as possible. Satisfactory short-term efficacy can be obtained, but long-term neurological sequelae often linger.

Rapid and inexpensive bedside diagnosis of RAN binding protein 2-associated acute necrotizing encephalopathy

Acute necrotizing encephalopathy 1 (ANE1) is a very rare disorder associated with a dominant heterozygous mutation in the RANBP2 (RAN binding protein 2) gene. ANE1 is frequently triggered by a febrile infection and characterized by serious and irreversible neurological damage. Although only a few hundred cases have been reported, mutations in RANBP2 are only partially penetrant and can occur de novo, suggesting that their frequency may be higher in some populations. Genetic diagnosis is a lengthy process, potentially delaying definitive diagnosis. We therefore developed a rapid bedside qPCR-based tool for early diagnosis and screening of ANE1 mutations. Primers were designed to specifically assess RANBP2 and not RGPD (RANBP2 and GCC2 protein domains) and discriminate between wild-type or mutant RANBP2. Nasal epithelial cells were obtained from two individuals with known RANBP2 mutations and two healthy control individuals. RANBP2-specific reverse transcription followed by allele-specific primer qPCR amplification confirmed the specific detection of heterozygously expressed mutant RANBP2 in the ANE1 samples. This study demonstrates that allele-specific qPCR can be used as a rapid and inexpensive diagnostic tool for ANE1 using preexisting equipment at local hospitals. It can also be used to screen non-hospitalized family members and at risk-population to better establish the frequency of non-ANE-associated RANBP2 mutations, as well as possible tissue-dependent expression patterns.

Systematic review registration

The protocol was registered in the international prospective register of systematic reviews (PROSPERO- CRD42023443257).

Exploring the molecular and clinical spectrum of COVID-19-related acute necrotizing encephalopathy in three pediatric cases

Acute necrotizing encephalopathy (ANE) is a rare disease that predominantly affects children and is associated with a high mortality rate. Here we report three cases of COVID-19-related ANE in children, with the mutation detection in two genes associated with mitochondrial dysfunction. The cases exhibited common ANE symptoms, such as fever, impaired consciousness, positive pathological reflex, increased cerebrospinal fluid protein, and multifocal and symmetric brain lesions identified through MRI. Using genotype-phenotype correlation analysis in trio-whole exome sequencing (WES), four potential pathogenic variants were identified in two genes associated with mitochondrial function (RANBP2 and MCCC2). Notably, MCCC2 was identified as being potentially associated with COVID-19-related ANE for the first time, and two of the four variants had not been previously reported. Our findings expand the clinical and mutation spectrum of COVID-19-related ANE in pediatric cases. The finding of these three new cases in our study further supports the previous hypothesis about the role of mitochondrial homeostatic imbalance in COVID-19-related ANE. It is essential to use genetic testing to identify this subset of patients with compromised mitochondrial function in order to improve patient management and prognosis.

From the sideline: Tissue-specific nucleoporin function in health and disease, an update

The subcellular compartmentalisation of eukaryotic cells requires selective exchange between the cytoplasm and the nucleus. Intact nucleocytoplasmic transport is vital for normal cell function and mutations in the executing machinery have been causally linked to human disease. Central players in nucleocytoplasmic exchange are nuclear pore complexes (NPCs), which are built from ~30 distinct proteins collectively termed nucleoporins. Aberrant nucleoporin expression was detected in human cancers and autoimmune diseases since quite some time, while it was through the increasing use of next generation sequencing that mutations in nucleoporin genes associated with mainly rare hereditary diseases were revealed. The number of newly identified mutations is steadily increasing, as is the number of diseases. Mutational hotspots have emerged: mutations in the scaffold nucleoporins seemingly affect primarily inner organs, such as heart, kidney, and ovaries, whereas genetic alterations in peripheral, cytoplasmic nucleoporins affect primarily the central nervous system and development. In this review, we summarise latest insights on altered nucleoporin function in the context of human hereditary disorders, with a focus on those where mechanistic insights are beginning to emerge.

Acute necrotizing encephalopathy associated with COVID-19: case series and systematic review

Acute necrotizing encephalopathy (ANE) is a rare neurological complication related to COVID-19. Here we present a case series of six Chinese cases with ANE associated with COVID-19 and review all reported cases in the literature. A total of six cases with ANE related to COVID-19 were enrolled in this study. Clinical manifestations, neuroimaging data, treatment and outcomes of these patients were analyzed. A literature review was performed in Pubmed and Embase and 25 cases with clinical and neuroimaging data were collected and analyzed. Among our six cases, the age of onset ranged from 15 to 56 years, with a male-to-female ratio of nearly 1:1. All patients presented with reduced consciousness. Elevated interleukin 6 in serum and/or cerebrospinal fluid (CSF) was detected in four patients. Two patients improved clinically after intravenous methylprednisolone and intravenous immunoglobulin (IVIG). Based on the literature review, the majority of cases were from Europe and the United States (60%). Two age peaks at 10-20 years (20%) and 50-60 years (28%) were observed. Two cases were found with a heterozygous Thr585Met mutation. The mortality of ANE caused by COVID-19 was 42%. The use of IVIG in combination with other immunotherapies was related to better outcome (P = 0.041) and both two patients who received Tocilizumab survived. This is the first Chinese case series about ANE associated with COVID-19. Elevated serum and CSF interlukin-6 were found in certain cases. The mortality and morbidity rates remained high although prompt immunotherapy could improve the outcomes.

RANBP2 evolution and human disease

Ran-binding protein 2 (RANBP2)/Nup358 is a nucleoporin and a key component of the nuclear pore complex. Through its multiple functions (e.g., SUMOylation, regulation of nucleocytoplasmic transport) and subcellular localizations (e.g., at the nuclear envelope, kinetochores, annulate lamellae), it is involved in many cellular processes. RANBP2 dysregulation or mutation leads to the development of human pathologies, such as acute necrotizing encephalopathy 1, cancer, neurodegenerative diseases, and it is also involved in viral infections. The chromosomal region containing the RANBP2 gene is highly dynamic, with high structural variation and recombination events that led to the appearance of a gene family called RANBP2 and GCC2 Protein Domains (RGPD), with multiple gene loss/duplication events during ape evolution. Although RGPD homoplasy and maintenance during evolution suggest they might confer an advantage to their hosts, their functions are still unknown and understudied. In this review, we discuss the appearance and importance of RANBP2 in metazoans and its function-related pathologies, caused by an alteration of its expression levels (through promotor activity, post-transcriptional, or post-translational modifications), its localization, or genetic mutations.

Recurrent Episodes of Encephalopathy/Encephalitis Secondary to Influenza Virus in a Pediatric Patient

Influenza virus commonly causes acute upper respiratory tract infections in pediatrics. Rarely, influenza-associated encephalopathy/encephalitis may occur in 4 of 100,000 children annually in the United States. North American literature, however, is sparse regarding the incidence of recurrent episodes. This report characterizes the clinical manifestations and identifies genetic, virologic and/or epidemiologic factors making children susceptible for recurring episodes of influenza-associated encephalopathy/encephalitis.

Expert Panel Curation of 113 Primary Mitochondrial Disease Genes for the Leigh Syndrome Spectrum

OBJECTIVE

Primary mitochondrial diseases (PMDs) are heterogeneous disorders caused by inherited mitochondrial dysfunction. Classically defined neuropathologically as subacute necrotizing encephalomyelopathy, Leigh syndrome spectrum (LSS) is the most frequent manifestation of PMD in children, but may also present in adults. A major challenge for accurate diagnosis of LSS in the genomic medicine era is establishing gene-disease relationships (GDRs) for this syndrome with >100 monogenic causes across both nuclear and mitochondrial genomes.

METHODS

The Clinical Genome Resource (ClinGen) Mitochondrial Disease Gene Curation Expert Panel (GCEP), comprising 40 international PMD experts, met monthly for 4 years to review GDRs for LSS. The GCEP standardized gene curation for LSS by refining the phenotypic definition, modifying the ClinGen Gene-Disease Clinical Validity Curation Framework to improve interpretation for LSS, and establishing a scoring rubric for LSS.

RESULTS

The GDR with LSS across the nuclear and mitochondrial genomes was classified as definitive for 31 of 114 GDRs curated (27%), moderate for 38 (33%), limited for 43 (38%), and disputed for 2 (2%). Ninety genes were associated with autosomal recessive inheritance, 16 were maternally inherited, 5 were autosomal dominant, and 3 were X-linked.

INTERPRETATION

GDRs for LSS were established for genes across both nuclear and mitochondrial genomes. Establishing these GDRs will allow accurate variant interpretation, expedite genetic diagnosis of LSS, and facilitate precision medicine, multisystem organ surveillance, recurrence risk counseling, reproductive choice, natural history studies, and determination of eligibility for interventional clinical trials. ANN NEUROL 2023;94:696-712.

Case report: Acute necrotizing encephalopathy: a report of a favorable outcome and systematic meta-analysis of outcomes with different immunosuppressive therapies

Acute Necrotizing Encephalopathy (ANE) is a condition characterized by symmetric, bilateral lesions affecting the thalamus and potentially other areas of the brain following an acute febrile illness. It manifests clinically as abrupt development of encephalopathy, or alteration in mental status that often includes development of seizures and progression to coma. Treatment strategies combine immunosuppressive therapies and supportive care with varying levels of recovery, however there are no universally accepted, data-driven, treatment algorithms for ANE. We first report a case of a previously healthy 10-year-old female with acute onset diplopia, visual hallucinations, lethargy, and seizures in the setting of subacute non-specific viral symptoms and found to have bilateral thalamic and brainstem lesions on MRI consistent with ANE. She was treated with a combination of immunomodulatory therapies and ultimately had a good outcome. Next, we present a meta-analysis of 10 articles with a total of 158 patients meeting clinical and radiographic criteria for ANE. Each article reported immunosuppressive treatments received, and associated morbidity or mortality outcome for each individual patient. Through our analysis, we confirm the effectiveness of high-dose, intravenous, methylprednisolone (HD-IV-MP) therapy implemented early in the disease course (initiation within 24 h of neurologic symptom onset). There was no significant difference between patients treated with and without intravenous immunoglobulin (IVIG). There was no benefit of combining IVIG with early HD-IV-MP. There is weak evidence suggesting a benefit of IL-6 inhibitor tocilizumab, especially when used in combination with early HD-IV-MP, though this analysis was limited by sample size. Finally, plasma exchange (PLEX) improved survival. We hope this meta-analysis will be useful for clinicians making treatment decisions for patients with this potentially devastating condition.

Biallelic variants in ribonuclease inhibitor (RNH1), an inflammasome modulator, are associated with a distinctive subtype of acute, necrotizing encephalopathy

PURPOSE

Mendelian etiologies for acute encephalopathies in previously healthy children are poorly understood, with the exception of RAN binding protein 2 (RANBP2)-associated acute necrotizing encephalopathy subtype 1 (ANE1). We provide clinical, genetic, and neuroradiological evidence that biallelic variants in ribonuclease inhibitor (RNH1) confer susceptibility to a distinctive ANE subtype.

METHODS

This study aimed to evaluate clinical data, neuroradiological studies, genomic sequencing, and protein immunoblotting results in 8 children from 4 families who experienced acute febrile encephalopathy.

RESULTS

All 8 healthy children became acutely encephalopathic during a viral/febrile illness and received a variety of immune modulation treatments. Long-term outcomes varied from death to severe neurologic deficits to normal outcomes. The neuroradiological findings overlapped with ANE but had distinguishing features. All affected children had biallelic predicted damaging variants in RNH1: a subset that was studied had undetectable RNH1 protein. Incomplete penetrance of the RNH1 variants was evident in 1 family.

CONCLUSION

Biallelic variants in RNH1 confer susceptibility to a subtype of ANE (ANE2) in previously healthy children. Intensive immunological treatments may alter outcomes. Genomic sequencing in children with unexplained acute febrile encephalopathy can detect underlying genetic etiologies, such as RNH1, and improve outcomes in the probands and at-risk siblings.

Association of IL6 and IL10 gene promotor polymorphisms with susceptibility to acute necrotizing encephalopathy

Objective

Acute necrotizing encephalopathy (ANE) is a severe complication of infectious diseases affecting the brain and systemic organs. The main pathogenesis is cytokine storm, in which interleukin-6 (IL-6) and interleukin-10 (IL-10) are candidates for key cytokines. To further elucidate their roles in the etiology and pathogenesis of ANE, we studied polymorphisms in the promotor regions of the IL6 and IL10 genes by genetic and functional analyses.

Methods

We first conducted a case-control association study of four IL6 and three IL10 polymorphisms. We genotyped 31 Japanese ANE cases and compared the results with those of approximately 200 Japanese controls. For the two polymorphisms showing a possible association, we next studied whether the polymorphisms alter the production of IL-6 or IL-10 by lymphoblasts upon phorbol 12-myristate 13-acetate (PMA) stimulation.

Results

The frequencies of IL6 rs1800796G allele and IL10 rs1800871/rs1800872 CC/CC diplotype were significantly higher in ANE cases than in controls. The IL10 CC/CC diplotype was associated with low IL-10 production, whereas the IL6 GG genotype was not associated with IL-6 production.

Conclusion

IL10 rs1800871/rs1800872 CC/CC diplotype may predispose Japanese children to ANE by altering IL-10 production in the early phase of infection. Etio-pathogenetic significance of IL6 rs1800796G remains to be elucidated.

Treatment of severe acute necrotizing encephalopathy of childhood with interleukin-6 receptor blockade in the first 24 h as add-on immunotherapy shows favorable long-term outcome at 2 years

BACKGROUND

Acute necrotizing encephalopathy (ANE) of childhood is a rare and devastating infection-associated acute encephalopathy. While there are no consensus treatments for ANE, recent case reports suggest a beneficial role for the use of tocilizumab, a recombinant humanized monoclonal antibody against the interleukin-6 (IL-6) receptor. The correlation of the timing of add-on tocilizumab in relation to long-term outcome has not been reported.

METHODS

We report on the timing of administration of tocilizumab in two patients classified as high-risk using the ANE severity score (ANE-SS) with respect to the long-term outcome at 2 years.

RESULTS

Case 1 was a 19-month-old previously well boy who presented to a tertiary children's hospital with seizures, evolving status dystonicus and shock. Case 2 was a three-year-old boy who presented to a peripheral hospital with fever, sepsis and encephalopathy. The patients were transferred to the tertiary intensive care unit and MRI confirmed ANE with extensive brainstem involvement. Case 1 received intravenous immunoglobulin (IVIg), methylprednisolone and tocilizumab at 21, 39 and 53 h respectively. His modified Rankin scale (mRS) at discharge and two years was unchanged at 5. The functional independence measure - for children (WeeFIM) at two years was very low (19/126). Case 2 received dexamethasone at 1 h, methylprednisolone at 21 h and IVIg and tocilizumab at 22 h. The mRS at discharge and two years was 4 and 3 respectively. The WeeFIM score at two years showed substantial improvement (96/126).

CONCLUSION

The very early use of interleukin-6 blockade as 'add-on' immunotherapy in the first 24 h demonstrates potential for improving the long-term outcome in patients classified as high-risk using the ANE-SS.

Nucleoporin Seh1 maintains Schwann cell homeostasis by regulating genome stability and necroptosis

Schwann cells play critical roles in peripheral neuropathies; however, the regulatory mechanisms of their homeostasis remain largely unknown. Here, we show that nucleoporin Seh1, a component of nuclear pore complex, is important for Schwann cell homeostasis. Expression of Seh1 decreases as mice age. Loss of Seh1 leads to activated immune responses and cell necroptosis. Mice with depletion of Seh1 in Schwann cell lineage develop progressive reduction of Schwann cells in sciatic nerves, predominantly non-myelinating Schwann cells, followed by neural fiber degeneration and malfunction of the sensory and motor system. Mechanistically, Seh1 safeguards genome stability by mediating the interaction between SETDB1 and KAP1. The disrupted interaction after ablation of Seh1 derepresses endogenous retroviruses, which triggers ZBP1-dependent necroptosis in Schwann cells. Collectively, our results demonstrate that Seh1 is required for Schwann cell homeostasis by maintaining genome integrity and suggest that decrease of nucleoporins may participate in the pathogenesis of periphery neuropathies.

Expression of targets of the RNA-binding protein AUF-1 in human airway epithelium indicates its role in cellular senescence and inflammation

Introduction

The RNA-binding protein AU-rich-element factor-1 (AUF-1) participates to posttranscriptional regulation of genes involved in inflammation and cellular senescence, two pathogenic mechanisms of chronic obstructive pulmonary disease (COPD). Decreased AUF-1 expression was described in bronchiolar epithelium of COPD patients versus controls and in vitro cytokine- and cigarette smoke-challenged human airway epithelial cells, prompting the identification of epithelial AUF-1-targeted transcripts and function, and investigation on the mechanism of its loss.

Results

RNA immunoprecipitation-sequencing (RIP-Seq) identified, in the human airway epithelial cell line BEAS-2B, 494 AUF-1-bound mRNAs enriched in their 3'-untranslated regions for a Guanine-Cytosine (GC)-rich binding motif. AUF-1 association with selected transcripts and with a synthetic GC-rich motif were validated by biotin pulldown. AUF-1-targets' steady-state levels were equally affected by partial or near-total AUF-1 loss induced by cytomix (TNFα/IL1β/IFNγ/10 nM each) and siRNA, respectively, with differential transcript decay rates. Cytomix-mediated decrease in AUF-1 levels in BEAS-2B and primary human small-airways epithelium (HSAEC) was replicated by treatment with the senescence- inducer compound etoposide and associated with readouts of cell-cycle arrest, increase in lysosomal damage and senescence-associated secretory phenotype (SASP) factors, and with AUF-1 transfer in extracellular vesicles, detected by transmission electron microscopy and immunoblotting. Extensive in-silico and genome ontology analysis found, consistent with AUF-1 functions, enriched RIP-Seq-derived AUF-1-targets in COPD-related pathways involved in inflammation, senescence, gene regulation and also in the public SASP proteome atlas; AUF-1 target signature was also significantly represented in multiple transcriptomic COPD databases generated from primary HSAEC, from lung tissue and from single-cell RNA-sequencing, displaying a predominant downregulation of expression.

Discussion

Loss of intracellular AUF-1 may alter posttranscriptional regulation of targets particularly relevant for protection of genomic integrity and gene regulation, thus concurring to airway epithelial inflammatory responses related to oxidative stress and accelerated aging. Exosomal-associated AUF-1 may in turn preserve bound RNA targets and sustain their function, participating to spreading of inflammation and senescence to neighbouring cells.

Pathogenesis and Management of Acute Necrotizing Encephalopathy

INTRODUCTION

During the COVID-19 pandemic, many cases of acute necrotizing encephalopathy (ANE) secondary to COVID-19 have been reported. ANE is characterized by a rapid onset, a fulminant course, and low morbidity and fatality rates. Therefore, clinicians need to be vigilant for such disorders, especially during the influenza virus and COVID-19 epidemics.

AREAS COVERED

The authors summarize the most recent studies on the clinical spectrum and treatment essentials of ANE to provide references for prompt diagnosis and improved treatment of this rare but fatal disease.

EXPERT OPINION

ANE is a type of necrotizing lesion of the brain parenchyma. There are two major types of reported cases. One is isolated and sporadic ANE, which is primarily caused by viral infections, particularly influenza and HHV-6 virus. The other type is familial recurrent ANE, which is caused by RANBP2 gene mutations. ANE patients have rapid progression and a very poor prognosis, with acute brain dysfunction occurring within days of viral infection and requiring admission to the intensive care unit. Clinicians still need to investigate and find solutions for the problems of early detection and treatment of ANE.

Integrated multi-omics for rapid rare disease diagnosis on a national scale

Critically ill infants and children with rare diseases need equitable access to rapid and accurate diagnosis to direct clinical management. Over 2 years, the Acute Care Genomics program provided whole-genome sequencing to 290 families whose critically ill infants and children were admitted to hospitals throughout Australia with suspected genetic conditions. The average time to result was 2.9 d and diagnostic yield was 47%. We performed additional bioinformatic analyses and transcriptome sequencing in all patients who remained undiagnosed. Long-read sequencing and functional assays, ranging from clinically accredited enzyme analysis to bespoke quantitative proteomics, were deployed in selected cases. This resulted in an additional 19 diagnoses and an overall diagnostic yield of 54%. Diagnostic variants ranged from structural chromosomal abnormalities through to an intronic retrotransposon, disrupting splicing. Critical care management changed in 120 diagnosed patients (77%). This included major impacts, such as informing precision treatments, surgical and transplant decisions and palliation, in 94 patients (60%). Our results provide preliminary evidence of the clinical utility of integrating multi-omic approaches into mainstream diagnostic practice to fully realize the potential of rare disease genomic testing in a timely manner.

Acute Necrotizing Encephalitis Due to Influenza B in a Child: A Case Report

Acute necrotizing encephalitis (ANE) is a rare and life-threatening form of encephalitis associated with influenza virus and other pathogens. It is characterized by a rapid onset of neurological symptoms and has been linked to a cytokine storm within the brain. We present a unique case of an eight-year-old female with influenza B-associated ANE, involving multiple brain areas including the cerebellum and brainstem and cauda equina involvement. The patient had a rapid neurological deterioration, and MRI findings revealed extensive multifocal areas of abnormal brain parenchyma and inflammation with Guillain-Barre appearance in the cauda equina. To the best of our knowledge, this is the first reported case of ANE with cauda equina involvement leading to neurological deficits. Despite treatment with oseltamivir, steroids, and intravenous immunoglobulins, the patient had poor neurological outcomes, similar to those reported in the literature.

Neurological features related to influenza virus in the pediatric population: a 3-year monocentric retrospective study

Influenza virus is generally characterized by fever, myalgia, and respiratory symptoms. Neurological entities have already been described, such as acute necrotizing encephalitis (ANE). We aimed to highlight the non-exceptional nature and explore the clinical spectrum and evolution of neurological features related to influenza virus in children. This monocentric observational study included patients under 18 years old, positive for influenza virus, between January 2017 and April 2019 in a pediatric university hospital. Patients were classified into two groups: those with or without a previous significant neurological or metabolic disorder. Two hundred eighty-nine children were identified with influenza infection. Thirty seven had a neurological manifestation: 14 patients who had previous significant neurological or metabolic disorder and 23 patients with no medical history. We identified several clinical patterns: 22 patients had seizures, 7 behavior disorders, 5 disturbances of consciousness, and 3 motor deficits. Four were diagnosed with a known influenza-associated neurological syndrome: 1 ANE, 1 cytotoxic lesion of the corpus callosum, 1 hemiconvulsion-hemiplegia-epilepsia syndrome, and 1 recurrent encephalitis in the context of a RANBP2 mutation. The neurological outcome was favorable in most cases. None of the patients with previous significant disorder retained sequalae or had a recurrence. Two patients had a fatal outcome, and both had a predisposing disorder.

CONCLUSION

Various neurological manifestations can be associated with influenza virus. Certain entities led to a poor prognosis, but in most cases, symptoms improved within a few days. The severity of the neurological manifestations correlated with previous neurological or metabolic disorders.

WHAT IS KNOWN

• Influenza viruses are well known pathogens with a seasonal epidemic evolution, particularly affecting children. These viruses cause acute fever with respiratory symptoms, associated with myalgia and headaches. Neurological presentation in influenza-virus infection is a well-established possibility as influenza virus is considered to be responsible for 27 to 36% of childhood encephalitis. Some specific and severe entity as acute necrotizing encephalitis, cytotoxic lesion of the corpus callosum, or Hemiconvulsion-hemiplegia-epilepsy syndrome are well described.

WHAT IS NEW

• In a French monocentric cohort of 37 children with influenza-related neurologic manifestations, the majority of these manifestations, including seizure, drowsiness, motor deficiency, hallucination… are self limiting and do not lead to after-effects. In rare cases (4/37), they may reveal severe encephalitis requiring rapid and appropriate treatment. Otherwise, comparison of a group of 14 children with underlying neurological or metabolic disorder with a group of 23 children free of any significant disorder show that the severity of the neurological manifestations was largely related to previous neurological or metabolic disorders highlighting the importance of vaccination in this population.

Genetic and environmental risk factors of acute infection-triggered encephalopathy

Acute encephalopathy is a constellation of syndromes in which immune response, metabolism and neuronal excitation are affected in a variable fashion. Most of the syndromes are complex disorders, caused or aggravated by multiple, genetic and environmental risk factors. Environmental factors include pathogenic microorganisms of the antecedent infection such as influenza virus, human herpesvirus-6 and enterohemorrhagic Escherichia coli, and drugs such as non-steroidal anti-inflammatory drugs, valproate and theophylline. Genetic factors include mutations such as rare variants of the SCN1A and RANBP2 genes, and polymorphisms such as thermolabile CPT2 variants and HLA genotypes. By altering immune response, metabolism or neuronal excitation, these factors complicate the pathologic process. On the other hand, some of them could provide promising targets to prevent or treat acute encephalopathy.

Infection and inflammation: radiological insights into patterns of pediatric immune-mediated CNS injury

The central nervous system (CNS) undergoes constant immune surveillance enabled via regionally specialized mechanisms. These include selectively permissive barriers and modifications to interlinked innate and adaptive immune systems that detect and remove an inciting trigger. The end-points of brain injury and edema from these triggers are varied but often follow recognizable patterns due to shared underlying immune drivers. Imaging provides insights to understanding these patterns that often arise from unique interplays of infection, inflammation and genetics. We review the current updates in our understanding of these intersections and through examples of cases from our practice, highlight that infection and inflammation follow diverse yet convergent mechanisms that can challenge the CNS in children.

Severe pediatric acute encephalopathy syndromes related to SARS-CoV-2

Background and objectives

To clarify whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection cause acute encephalopathy in children and which are the most common syndromes that cause them and what are the outcomes.

Methods

A nationwide web-based survey among all members of the Japanese Society of Child Neurology to identify pediatric patients aged < 18 years who developed acute encephalopathy in Japan between 1 January 2020 and 31 May 2022 associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection confirmed by polymerase chain reaction or antigen tests using pharyngeal swabs. Acute encephalopathy was defined as acute onset of impaired consciousness lasting > 24 h or an altered mental state; neurological symptoms arising within 2 weeks of onset of COVID-19 or multisystem inflammatory syndrome in children (MIS-C)/pediatric inflammatory multisystem syndrome (PIMS); evidence of SARS-CoV-2 infection; and reasonable exclusion of other diseases. Patients were divided into the known clinico-radiological acute encephalopathy syndrome group and unexplained or unclassifiable acute encephalopathy group. Outcomes were assessed by pediatric cerebral performance category (PCPC) score at hospital discharge.

Results

Of the 3,802 society members, 217 representing institutions responded, and 39 patients with suspected acute encephalopathy were reported, of which 31 met inclusion criteria. Of these patients, 14 were diagnosed with known clinico-radiological acute encephalopathy syndromes, with acute encephalopathy with biphasic seizures and late reduced diffusion (five patients) being the most common. Five developed acute encephalopathy associated with MIS-C/PIMS. Among 31 patients, 9 (29.0%) had severe sequelae or died (PCPC ≥ 4). Two of three patients with encephalopathy with acute fulminant cerebral edema and two with hemorrhagic shock and encephalopathy syndrome died. The PCPC scores were higher in the known clinico-radiological acute encephalopathy syndrome group than in the unexplained or unclassifiable acute encephalopathy group (P < 0.01).

Discussion

Acute encephalopathy related to SARS-CoV-2 infection was demonstrated to be more severe than that caused by other viruses in Japan. Acute encephalopathy syndromes characterized by specific neuroradiological findings was associated with poor clinical outcomes.

Pediatric recurrent acute necrotizing encephalomyelitis, RANBP2 genotype and Sars-CoV-2 infection: Diagnosis, pathogenesis and targeted treatments from a case study

Acute necrotizing encephalopathy (ANE) is a rare disease not yet described in children with Covid-19. RANBP2 gene variations are implicated in recurrences in the genetic form of ANE, the so called ANE1. We report the first case of pediatric ANE1 following Sars-CoV-2 infection. She had a first episode at 2 years of age following influenza type A with full recovery, many other respiratory and non-respiratory febrile viral infections without recurrences and a severe recurrence following Sars-CoV-2 infection, suggesting a potentiation effect on cytokine cascade. Her MRI showed the typical pattern of injury resembling that of mitochondrial disorders, and supported the role of RANBP2 in mitochondrial homeostasis. This case rises attention on diagnostic challenges and offers several interesting tips for discussion about new perspectives in pathogenesis and targeted treatments.

Acute necrotizing encephalopathy associated with RANBP2 mutation: value of MRI findings for diagnosis and intervention

INTRODUCTION

Acute necrotizing encephalopathy (ANEC) is a rare entity characterized by encephalopathy following a febrile illness. Most patients are sporadic; however, recurrent and familial cases have been associated with RAN-binding protein 2 (RANBP2) mutation. Well-defined MRI findings can even be life-saving with early diagnosis and treatment.

METHODS

In this article, nine pediatric cases diagnosed with ANEC1 both clinically and radiologically, and with least one variation in the RANBP2 gene, are presented.

RESULTS

All patients were previously healthy and presented with encephalopathy after an acute febrile infection. The patients of 44% had a similar attack history in their family. Influenza A/B was detected in 7 patients (78%). One patient was admitted at age 32 years old. The first clinical findings of patients were encephalopathy (100%), seizure (44%), vision problems (33%), ataxia (11%), and monoplegia (11%). Recurrent attacks were seen in two (22%) patients. Brain MRI findings including bilateral thalamus, external capsules, and brainstem involvements were highly suggestive for RANBP2 mutation. Based on MRI findings, genetic analyses were quickly performed and confirmed. All of the patients were treated with empirical encephalitis treatment, oseltamivir, intravenous immunoglobulin (IVIG), high-dose steroid and, if necessary, plasmapheresis, but three (33%) patients died despite treatment.

CONCLUSION

ANEC associated with RANBP2 mutation may occur early or late-onset and can be recurrent and fatal. Therefore, early diagnosis and treatment have the potential to modify the severity of this encephalopathy. Well-defined MRI findings are highly instructive for early diagnosis.

COVID-19 related acute necrotizing encephalopathy with extremely high interleukin-6 and RANBP2 mutation in a patient with recently immunized inactivated virus vaccine and no pulmonary involvement

Background

We report the first case of COVID-19 associated acute necrotizing encephalopathy (ANE) without pulmonary disease in a patient with an extremely high interleukin-6 (IL-6) level and Ran Binding Protein 2 (RANBP2) mutation.

Case presentation

A 29-year-old woman recently immunized with inactivated viral vaccine—BBIBP32-CorV (Sinopharm) presented with alteration of consciousness. Her body temperature was 37° Celsius, blood pressure 42/31 mmHg, heart rate 130 bpm, respiratory rate 20 per minute, and oxygen saturation 98%. Respiratory examination was unremarkable. Neurological examination revealed stupor but preserved brainstem reflexes. Non-contrast computerized tomography of the brain showed symmetrical hypodense lesions involving bilateral thalami and cerebellar hemispheres characteristic of ANE. No pulmonary infiltration was found on chest radiograph. SARS-CoV-2 was detected by PCR; whole genome sequencing later confirmed the Delta variant. RANBP2 gene analysis revealed heterozygous Thr585Met mutation. Serum IL-6 was 7390 pg/mL. Urine examination showed pyelonephritis. Her clinical course was complicated by seizure, septic shock, acute kidney injury, and acute hepatic failure. She later developed coma and passed away in 6 days.

Conclusions

ANE is caused by cytokine storm leading to necrosis and hemorrhage of the brain. IL-6 was deemed as a prognostic factor and a potential treatment target of ANE in previous studies. RANBP2 missense mutation strongly predisposes this condition by affecting mitochondrial function, viral entry, cytokine signaling, immune response, and blood–brain barrier maintenance. Also, inactivated vaccine has been reported to precipitate massive production of cytokines by antibody dependent enhancement (ADE). The true incidence of COVID-19 associated ANE is not known as were the predictors of its development. We proposed these potential two factors (RANBP2 mutation and ADE) that could participate in the pathogenesis of ANE in COVID-19 apart from SARS-CoV2 infection by itself. Further study is needed to confirm this hypothesis, specifically in the post-vaccination period. Role of RANBP2 mutation and its application in COVID-19 and ANE should be further elaborated.

Recurrent acute hemorrhagic necrotizing encephalopathy associated with RAN-binding protein-2 gene mutation in a pediatric patient

A young male child presented with recurrent episodes of seizures and altered mental status following febrile episodes on three separate occasions between his first and third birthdays. Laboratory evaluations identified SARS-CoV-2 infection during the first episode and no infective agents or antibodies in the cerebrospinal fluid during all the episodes. Brain imaging with CT and MRI revealed bilaterally symmetric patchy hemorrhagic necrotic foci in the deep brain nuclei and medial temporal lobes, prompting suspicion for an underlying predisposition to recurrent acute hemorrhagic necrotizing encephalopathy. Gene analysis confirmed a mutation in the RAN-binding protein-2 (RANBP2) gene. The patient made good recovery following treatment with IVIG, steroids and plasmapheresis, and follow-up brain imaging showed no progression of brain lesions. Early suspicion from characteristic imaging features in appropriate clinical settings will inform timely appropriate treatment and better outcome. We therefore provided short review of imaging features of acute hemorrhagic necrotizing encephalopathy.

Positive Impact of Inpatient Respiratory Rehabilitation in a Rare Case of Acute Necrotizing Encephalopathy

Acute necrotizing encephalopathy, also known as acute necrotizing encephalopathy of childhood (ANEC) is a rare disorder characterized by respiratory or gastrointestinal infections, high fever, and rapid changes in consciousness and seizures. ANEC is a rare form of encephalopathy characterized by multiple bilateral brain lesions, primarily involving the thalami and putamina internal and external capsules, cerebellar white matter, and the brainstem segmentum. Here we present, a rare case of acute necrotizing encephalopathy in a pediatric patient, a 13-year-old boy, who was admitted with acute onset of fever. The fever was intermittent and high grade along with chills, rigor, and respiratory distress five days back. The chest x-ray showed heterogeneous opacities in bilateral lung fields. Thalami, brainstem, cerebellum, and white matter have all been shown to have a symmetric lesion in this disease on magnetic resonance imaging (MRI). Ventilation, immunoglobulin, and other supporting measures, as well as respiratory rehabilitation, were used to treat him. In pediatric intensive care units (PICU), physiotherapy is considered an important aspect of patient care. Respiratory rehabilitation included patients and their family member's counseling, airway clearance techniques, energy conservation methods, and adaptation to complex positions with the maintenance of oxygen saturation (SpO₂). We conclude Respiratory rehabilitation with efficient family counseling is effective in the overall improvement of the patient’s condition with acute respiratory failure in acute necrotizing encephalopathy.

Chromosome 2q12.3-q13 copy number variants in patients with neurodevelopmental disorders: genotype-phenotype correlation and new hotspots

INTRODUCTION

The complex structure of the chromosome 2q12.3-q13 region provides a high chance of recombination events between various low copy repeats (LCRs). Copy number variants (CNV) in this region are present in both healthy populations and individuals affected with developmental delay, autism and congenital anomalies. Variable expressivity, reduced penetrance and limited characterization of the affected genes have complicated the classification of the CNVs clinical significance.

METHODS

Chromosomal microarray analysis data were reviewed for 10 298 patients with neurodevelopmental disorders referred to the UPMC Medical Genetics and Genomics Laboratories. A genotype-phenotype correlation was performed among the patients harboring the 2q12.3-q13 CNVs with overlapping genomic intervals.

RESULTS

We identified 17 (1 in ~600) individuals with rare CNVs in the 2q12.3-q13 region, including nine patients with deletions, seven individuals with duplications and one patient who had both a deletion and a duplication. Likely pathogenic CNVs with the breakpoints between LCRs encompassing the potential dosage-sensitive genes BCL2L11, BUB1, FBLN7 and TMEM87B were the most common. CNVs were also observed between LCRs surrounding the RANBP2 and LIMS1 genes.

CONCLUSION

Our study provides evidence for pathogenic CNV hotspots within the chromosome 2q12.3-q13 region. We suggest CNV classification based on the affected interval and the involvement of potential dosage-sensitive genes in these patients.

Adult-onset Still's disease with concurrent acute necrotizing encephalopathy: a case report

Background

Acute necrotizing encephalopathy (ANE) is a rare encephalopathy characterized by multiple symmetrical brain lesions, mainly involving thalami. Adult-onset Still’s disease (AOSD) is a rare systemic inflammatory condition of unknown cause characterized by fever, sore throat, rash and joint pain. Both entities are considered to be triggered by infections and associated with hypercytokinemia.

Case presentation

A 46-year-old male was diagnosed with AOSD at local hospital because of 3-week-long high fever, sore throat, arthralgia, transient skin rash, lymphadenopathy, leukocytosis, hyperferritinemia, and absence of antinuclear antibodies (ANA) and rheumatoid factor (RF). Corticosteroids were not used because of delayed diagnosis. Three weeks after the onset, the patient suddenly fell unconscious and was transferred to our hospital. Brain CT and MRI revealed symmetrical lesions involving thalami, striatum and brain stem, consistent with ANE. One day after admission, his condition aggravated and brain CT revealed hemorrhage in the lesions. He died 3 days after admission.

Conclusion

We report a rare case of ANE preceded by AOSD. The underlying mechanism is still unclear. Early recognizing of the two conditions is difficult but prognostically important.

Somatic variants in diverse genes leads to a spectrum of focal cortical malformations

Post-zygotically acquired genetic variants, or somatic variants, that arise during cortical development have emerged as important causes of focal epilepsies, particularly those due to malformations of cortical development. Pathogenic somatic variants have been identified in many genes within the PI3K-AKT-mTOR-signalling pathway in individuals with hemimegalencephaly and focal cortical dysplasia (type II), and more recently in SLC35A2 in individuals with focal cortical dysplasia (type I) or non-dysplastic epileptic cortex. Given the expanding role of somatic variants across different brain malformations, we sought to delineate the landscape of somatic variants in a large cohort of patients who underwent epilepsy surgery with hemimegalencephaly or focal cortical dysplasia. We evaluated samples from 123 children with hemimegalencephaly (n = 16), focal cortical dysplasia type I and related phenotypes (n = 48), focal cortical dysplasia type II (n = 44), or focal cortical dysplasia type III (n = 15). We performed high-depth exome sequencing in brain tissue-derived DNA from each case and identified somatic single nucleotide, indel and large copy number variants. In 75% of individuals with hemimegalencephaly and 29% with focal cortical dysplasia type II, we identified pathogenic variants in PI3K-AKT-mTOR pathway genes. Four of 48 cases with focal cortical dysplasia type I (8%) had a likely pathogenic variant in SLC35A2. While no other gene had multiple disease-causing somatic variants across the focal cortical dysplasia type I cohort, four individuals in this group had a single pathogenic or likely pathogenic somatic variant in CASK, KRAS, NF1 and NIPBL, genes previously associated with neurodevelopmental disorders. No rare pathogenic or likely pathogenic somatic variants in any neurological disease genes like those identified in the focal cortical dysplasia type I cohort were found in 63 neurologically normal controls (P = 0.017), suggesting a role for these novel variants. We also identified a somatic loss-of-function variant in the known epilepsy gene, PCDH19, present in a small number of alleles in the dysplastic tissue from a female patient with focal cortical dysplasia IIIa with hippocampal sclerosis. In contrast to focal cortical dysplasia type II, neither focal cortical dysplasia type I nor III had somatic variants in genes that converge on a unifying biological pathway, suggesting greater genetic heterogeneity compared to type II. Importantly, we demonstrate that focal cortical dysplasia types I, II and III are associated with somatic gene variants across a broad range of genes, many associated with epilepsy in clinical syndromes caused by germline variants, as well as including some not previously associated with radiographically evident cortical brain malformations.

First case with RANBP2 biallelic mutation and severe acute necrotizing encephalopathy phenotype

Familial acute necrotizing encephalopathy (ANE) is a rapidly progressive encephalopathy that can occur after common viral infections at different stages of life. The clinical findings of 2 siblings diagnosed with ANE were shared and the whole-exome-sequencing study of the index case was performed. It was confirmed by the Sanger method. We found the RANBP2 gene p.I656V variant homozygous in the index case. We found the variant in the parents as heterozygous. We argue that biallelic mutations in the RANBP2 gene may result in ANE with early onset and severe prognosis by increasing penetrance.